From af80602799681c78f14fbe20b6185a56020dedee Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 25 Oct 2022 21:38:18 +0200 Subject: mm: Move mm_cachep initialization to mm_init() In order to allow using mm_alloc() much earlier, move initializing mm_cachep into mm_init(). Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20221025201057.751153381@infradead.org --- kernel/fork.c | 32 ++++++++++++++++++-------------- 1 file changed, 18 insertions(+), 14 deletions(-) (limited to 'kernel/fork.c') diff --git a/kernel/fork.c b/kernel/fork.c index 08969f5aa38d..451ce8063f85 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -3015,10 +3015,27 @@ static void sighand_ctor(void *data) init_waitqueue_head(&sighand->signalfd_wqh); } -void __init proc_caches_init(void) +void __init mm_cache_init(void) { unsigned int mm_size; + /* + * The mm_cpumask is located at the end of mm_struct, and is + * dynamically sized based on the maximum CPU number this system + * can have, taking hotplug into account (nr_cpu_ids). + */ + mm_size = sizeof(struct mm_struct) + cpumask_size(); + + mm_cachep = kmem_cache_create_usercopy("mm_struct", + mm_size, ARCH_MIN_MMSTRUCT_ALIGN, + SLAB_HWCACHE_ALIGN|SLAB_PANIC|SLAB_ACCOUNT, + offsetof(struct mm_struct, saved_auxv), + sizeof_field(struct mm_struct, saved_auxv), + NULL); +} + +void __init proc_caches_init(void) +{ sighand_cachep = kmem_cache_create("sighand_cache", sizeof(struct sighand_struct), 0, SLAB_HWCACHE_ALIGN|SLAB_PANIC|SLAB_TYPESAFE_BY_RCU| @@ -3036,19 +3053,6 @@ void __init proc_caches_init(void) SLAB_HWCACHE_ALIGN|SLAB_PANIC|SLAB_ACCOUNT, NULL); - /* - * The mm_cpumask is located at the end of mm_struct, and is - * dynamically sized based on the maximum CPU number this system - * can have, taking hotplug into account (nr_cpu_ids). - */ - mm_size = sizeof(struct mm_struct) + cpumask_size(); - - mm_cachep = kmem_cache_create_usercopy("mm_struct", - mm_size, ARCH_MIN_MMSTRUCT_ALIGN, - SLAB_HWCACHE_ALIGN|SLAB_PANIC|SLAB_ACCOUNT, - offsetof(struct mm_struct, saved_auxv), - sizeof_field(struct mm_struct, saved_auxv), - NULL); vm_area_cachep = KMEM_CACHE(vm_area_struct, SLAB_PANIC|SLAB_ACCOUNT); mmap_init(); nsproxy_cache_init(); -- cgit v1.2.3 From 3f4c8211d982099be693be9aa7d6fc4607dff290 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 25 Oct 2022 21:38:21 +0200 Subject: x86/mm: Use mm_alloc() in poking_init() Instead of duplicating init_mm, allocate a fresh mm. The advantage is that mm_alloc() has much simpler dependencies. Additionally it makes more conceptual sense, init_mm has no (and must not have) user state to duplicate. Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20221025201057.816175235@infradead.org --- arch/x86/mm/init.c | 2 +- include/linux/sched/task.h | 1 - kernel/fork.c | 5 ----- 3 files changed, 1 insertion(+), 7 deletions(-) (limited to 'kernel/fork.c') diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c index 9121bc1b9453..d3987359d441 100644 --- a/arch/x86/mm/init.c +++ b/arch/x86/mm/init.c @@ -801,7 +801,7 @@ void __init poking_init(void) spinlock_t *ptl; pte_t *ptep; - poking_mm = copy_init_mm(); + poking_mm = mm_alloc(); BUG_ON(!poking_mm); /* diff --git a/include/linux/sched/task.h b/include/linux/sched/task.h index 8431558641a4..357e0068497c 100644 --- a/include/linux/sched/task.h +++ b/include/linux/sched/task.h @@ -91,7 +91,6 @@ extern void exit_itimers(struct task_struct *); extern pid_t kernel_clone(struct kernel_clone_args *kargs); struct task_struct *create_io_thread(int (*fn)(void *), void *arg, int node); struct task_struct *fork_idle(int); -struct mm_struct *copy_init_mm(void); extern pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags); extern pid_t user_mode_thread(int (*fn)(void *), void *arg, unsigned long flags); extern long kernel_wait4(pid_t, int __user *, int, struct rusage *); diff --git a/kernel/fork.c b/kernel/fork.c index 451ce8063f85..6142c588c18a 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -2592,11 +2592,6 @@ struct task_struct * __init fork_idle(int cpu) return task; } -struct mm_struct *copy_init_mm(void) -{ - return dup_mm(NULL, &init_mm); -} - /* * This is like kernel_clone(), but shaved down and tailored to just * creating io_uring workers. It returns a created task, or an error pointer. -- cgit v1.2.3